Method for the production of a portable integrated circuit electronic device comprising a low-cost dielectric

ABSTRACT

In a method for the production of a portable integrated circuit electronic device, an integrated circuit chip is transferred onto a dielectric support and connected to a metal grid comprising contact pads and connection pads. A housing is created for the chip on a metal grid by arching the grid. The dimensions of the housing enable the housing to accommodate the thickness of the card and the contact pads thereof. The grid is laminated on the dielectric support, whereby each contact pad of the card can be placed opposite to and in contact with the connection pads of the grid.

This disclosure is based upon French Application No. 99/06585, filed onMay 25, 1999 and International Application No. PCT/FR00/01268, filed May11, 2000, which was published on Nov. 30, 2000 in a language other thanEnglish, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to the manufacture of a portableelectronic device including at least one integrated-circuit chipembedded in a support and electrically connected to interface elementsconsisting of a connection terminal block and/or an antenna.

These portable electronic devices constitute for example smart cardswith and/or without contacts or electronic labels.

Smart cards with and/or without contacts are intended for performingvarious operations such as, for example, banking operations, telephonecommunications, various identification operations, or operations of thecash dispensing type.

Contact cards have metallisations flush with the surface of the card,disposed at a precise point on the card body, defined by the usualstandard ISO 7816. These metallisations are intended to come intocontact with a reading head of a reader with a view to an electricaltransmission of data.

Contactless cards have an antenna for exchanging information with theoutside by means of an electromagnetic coupling between the electronicsof the card and a receiving appliance or reader. This coupling can beeffected in read mode or in read/write mode, and the data transmissiontakes place by radio frequency or microwave.

There are also hybrid cards or “combicards” which have bothmetallisations flush with the surface of the card and an antennaembedded in the body of the card. This type of card can thereforeexchange data with the outside either in contact mode or withoutcontact.

As currently produced, the cards, with or without contact, are thinportable elements of standard dimensions. The standard ISO 7810corresponds to a card with a standard format 85 mm long, 54 mm wide and0.76 mm thick.

The majority of smart card manufacturing processes are based on theassembly of the integrated-circuit chip in a subassembly referred to asa micromodule which is connected to a communication interface and inset,that is to say placed in a cavity provided in a card body, usingtechniques known to experts.

A conventional manufacturing method is illustrated in FIG. 1. Such amethod consists in gluing an integrated-circuit chip 10, disposing itsactive face with its contact pads 11 upwards, and gluing its oppositeface to a dielectric support sheet 15. The dielectric sheet 15 is itselfdisposed on a contact grid 18 such as a metallic plate made from nickel-and gold-plated copper for example. Connection wells 16 are formed inthe dielectric sheet 15 in order to enable connection wires 17 toconnect the contact pads 11 on the chip 10 to the contact areas on thegrid 18.

According to some variants, it is possible to glue the chip 10, activeface upwards, directly on the contact grid 18, and then to connect it byhard wiring 17.

In such a variant, the grid 18 is deposited on a dielectric support 15and the contact connection areas on the said grid are defined bychemical etching or any other known means.

A protection or encapsulation step then protects the chip 10 and thesoldered connection wires 17. Use is generally made of a technique knownas “glob top” in English terminology, which designates the coating ofthe chip from above. This technique consists in pouring a drop of resin20, based on epoxy for example, thermosetting or cross-linking underultraviolet, on the chip 10 and its connection wires 17.

FIG. 2 illustrates a variant embodiment in which the chip 10 isconnected to the metallic grid 18 according to a “flip chips” method,which designates a known technique in which the chip is turned over.

In the example illustrated, the chip 10 is connected to the metallicgrid 18 by means of a glue 350 with anisotropic electrical conductionwhich is well known and often used for mounting passive components on asurface. The output pads 11 on the chip 10 are placed opposite theconnection areas on the grid 18. This glue 350 in fact containselastically deformable conductive particles which make it possible toestablish electrical conduction along the z axis (that is to say alongthe thickness) when they are pressed between the output pads 11 and theconnection areas on the grid 18, whilst providing insulation in theother directions (x,y).

In a variant embodiment, the electrical connection between the chip 10and the grid 18 can be improved by protrusions 12, made from hot-meltalloy of the Sn/Pb type or conductive polymer, produced on the pads 11on the chip 10.

The dielectric support 15 with the chip 10 glued and protected by theresin 20 is cut in order to constitute a micromodule 100.

In the case of a smart card with contact, the micromodule 100 is insetin the cavity in a previously decorated card body. This insettingoperation can be effected by depositing a liquid glue in the cavity ofthe card body before attaching the micromodule.

FIG. 3 illustrates another insetting technique. The card body 110 isproduced according to a conventional method, for example by injectingplastics material into a mould. The cavity 120 is obtained either bymilling the card body, or by injection at the time of the manufacture ofthe card body in an adapted mould.

A heat-activated adhesive film 23 is deposited by hot lamination on thedielectric film 15 preferentially before the cutting out of themicromodule 100. The latter is inset in the cavity 120 in the card body110 and glued by reactivating the heat-activated adhesive 23 by hotpressing by means of a press 24 whose shape is adapted to that of thecavity 120.

These known technologies for manufacturing contact cards have manydrawbacks.

They require in fact a large number of operations. When protection byresin is effected, it is generally necessary to mill the resin in orderto adapt its shape and thickness, which constitutes a tricky andexpensive operation and one which places a stress on the chip.

In particular, the standard technology uses expensive techniques and ahigh-quality dielectric. The dielectric used is generally made from aglass epoxy composite or Kapton.

This is because the dielectric chosen must have properties of goodresistance to temperature in order to be compatible with the insettingtechniques described above.

In addition, the geometric definition of the different contacts andconnection areas is generally obtained by chemical etching of themetallic grid deposited uniformly on the insulating support. However,chemical etching is an expensive operation.

In the case of a contactless smart card or an electronic label, themicromodule 100 is connected to an antenna 55, as illustrated forexample in FIG. 4.

The antenna 55 is produced on an insulating support 52 consisting of PVCor PE or any other suitable material (polyvinyl chloride, polyethylene).

The antenna 55 is produced from a conductive material, in a coil, byscreen printing with conductive ink, or by chemical etching of a metaldeposited on an insulating support. It can have the shape of a spiral orany other pattern according to the required applications.

The chip 10 is glued and connected to connection areas on a metallicgrid 18 by hard wiring 17 or according to any other known method, suchas “flip chip” for example.

The chip 10 and its connection wires 16 are then protected by a resin 20deposited according to the “glob top” technique described above, forexample.

The connection between the antenna 55 and the metallic grid 18 can beeffected by tin/lead soldering or by conductive gluing or lamination.

The body of the contactless card is then produced by hot lamination ofplastic films in order to have the final thickness or by lining a resinbetween the two dielectric sheets 15 and 52 separated by a strut.

In the case of an electronic label, the antenna, in its definitive form,is chosen by moulding the body of the label around the electronics or bylaminating plastic films or by inserting a plastic casing.

These known technologies for manufacturing contactless electronicdevices have many drawbacks.

The disadvantages cited above for contactless cards are found again inthe method of manufacturing contactless devices.

In addition, protecting the chip is tricky since effecting encapsulationis often impossible given the density of the module on the strip 52,which obliges the manufacturer to effect an overmoulding of themicromodule.

SUMMARY OF THE INVENTION

The aim of the present invention is to mitigate the drawbacks of theprior art.

To this end, the present invention proposes a method for manufacturingan electronic device making it possible to use inexpensive materials andin particular a less expensive dielectric.

In addition, the invention simplifies the step of connecting the chip byproducing a metallic grid which is arched so as to place the pads on thechip opposite the connection areas on the grid.

The object of the present invention is more particularly a method formanufacturing an integrated-circuit electronic device, anintegrated-circuit chip being attached to a dielectric support andconnected to a metallic grid having contact areas and connection areas,characterised in that it includes a step consisting of producing a chiphousing on a metallic grid by arching of the latter, the said housinghaving dimensions making it possible to receive the thickness of thechip and its contact pads, and in that the said grid is laminated on thedielectric support so as to place each contact pad on the chip oppositeand in connection with the said connection areas on the grid.

According to one characteristic of the invention, the dielectric supportconsists of a strip leaving the contact areas on the metallic grid free.

According to another characteristic of the invention, the metallic gridalso has a second arch able to encase the thickness of the dielectricstrip so as to place the latter flush with the contact areas on themetallic grid.

In a variant embodiment, the dielectric strip consists of a polyethyleneterephthalate (PET).

In another variant embodiment, the dielectric strip consists of anacrylonitrile butadiene-styrene (ABS).

In another variant embodiment, the dielectric strip consists of paper.

In another variant, the dielectric strip (60) consists of a polyvinylchloride (PVC).

According to one characteristic, the dielectric strip has an adhesivesurface able to provide the gluing of the chip on the said strip.

According to one characteristic, reference holes and/or targets areproduced on the dielectric strip so as to effect a precise gluing of thechip on the said strip.

According to a variant embodiment, the connection of the contact pads onthe chip to the connection areas on the grille is effected by laserwelding.

According to another variant embodiment, protrusions made fromconductive polymer material are deposited on the contact pads on thechip, the connection of the said contact pads to the connection areas onthe grille being effected by hot lamination.

According to a first application of the invention, the method includes astep of attaching the micromodule in the cavity of a card body.

The attaching of a micromodule is effected by activation of an adhesivefilm previously laminated over the entire surface of the metallic grid.

This adhesive film also constitutes an insulant providing the protectionof the chip.

According to a second application of the invention, the method includesa step of connecting the micromodule to an antenna.

The chip is then protected by lamination of an insulating film over theentire surface of the metallic grid.

Advantageously, the insulation of the central turns of the antenna isprovided by the dielectric strip.

The present invention also relates to an integrated-circuit electronicmodule, an integrated-circuit chip being attached to a dielectricsupport and connected to a communication interface having contact areasand connection areas, characterised in that the communication interfaceconsists of an arched metallic grid, the arch defining a chip housinghaving dimensions making it possible to receive the thickness of thechip and its contact pads, and in that the connection areas on the gridare situated opposite and in connection with the contact pads on thechip.

According to one characteristic, the dielectric support consists of astrip leaving the contact areas free.

According to another characteristic, the metallic grid has two distinctarches, a first arch encasing the thickness of the chip and its contactpads, and a second arch encasing the thickness of the dielectric strip.

According to one characteristic, a protective film is laminated over theentire surface of the metallic grid.

The present invention applies to any portable integrated-circuit devicesuch as smart cards or electronic labels, comprising an electronicmodule according to the invention.

The present invention makes it possible to obtain, with a simple andeconomical method, a thin electronic micromodule with good resistance tomoisture.

In particular, the method according to the invention makes it possibleto use a lower quality dielectric since the latter does not require theconventional properties of compatibility with the usual insettingtechniques.

This is because, and this will emerge more precisely below, thedielectric does not cover the contact areas of the metallic grid.However, during insetting, it is these areas which are pressed or gluedwith a glue of the cyanoacrylate type.

The method according to the invention has the advantage of being able tobe implemented in line without interruption.

In addition, the manufacturing method according to the invention has theadvantage of considerably simplifying the connection of the chips to theconnection areas on the grid.

In addition, the encapsulation and milling steps are completelyeliminated, since the chip is protected by the grid and a film laminatedover the entire surface of the grid.

BRIEF DESCRIPTION OF THE DRAWINGS

Other particularities and advantages of the invention will emerge from areading of the following description given by way of illustrative andnon-limitative example and made with reference to the accompanyingfigures, in which:

FIG. 1, already described, is a diagram in transverse sectionillustrating a traditional method for manufacturing a micromodule;

FIG. 2, already described, is a diagram in transverse sectionillustrating a traditional method for manufacturing a micromodule with avariant embodiment in the connection of the chip;

FIG. 3, already described, illustrates schematically the insetting of amicromodule according to a known method;

FIG. 4, already described, illustrates schematically the attachment of amicromodule to an antenna according to a known method;

FIG. 5 is a diagram in transverse section of a first embodiment of themanufacturing method according to the present invention;

FIG. 6 is a diagram in transverse section of a second embodiment of themanufacturing method according to the present invention;

FIG. 7 illustrates schematically the insetting of a micromoduleaccording to the method of the invention;

FIG. 8 is a schematic view from below, on the assembly side, of themicromodule obtained by the method according to the invention;

FIG. 9 is a schematic view from above, on the contact side, of themicromodule obtained by the method according to the invention;

FIG. 10 is a schematic diagram of the steps of manufacturing amicromodule according to the invention;

FIG. 11 is a schematic plan view of a third embodiment of themanufacturing method according to the invention;

FIG. 12 is a diagram in transverse section of the attachment of amicromodule according to the invention to a screen-printed antenna.

DESCRIPTION OF THE INVENTION

FIGS. 5 and 6 illustrate first and second embodiments of a micromoduleaccording to the invention.

These first two embodiments apply to smart cards with contact.

An integrated-circuit chip 10 is glued to a dielectric strip 60laminated on a metallic grid 18 arched once or twice, a first time forencasing the thickness of the chip 10 and its contact pads 11 so as toput the connection areas 19 b on the grid 18 opposite the contact pads11 on the chip 10, and a second time for encasing the thickness of thedielectric strip 60 so as to put the latter flush with the contact areas19 a on the grid 18.

Preferentially, protrusions 12 have previously been produced on eachcontact pad 11 on the chip 10. These protrusions 12 are intended toimprove the electrical connection between the contact pads 11 on thechip 10 and their connection areas 19 b on the grid 18. They areconsequently necessarily produced from a conductive material, such asfor example gold, or from a polymer material loaded with metallicparticles.

A protective film 25, having cross-linking adhesive properties, islaminated over the entire surface of the grid 18. This film 25 is notperforated, as was the case in the prior art, in order to leave the chip10 and its connections free.

The manufacturing method according to the invention comprises at leastthe following steps.

These steps are illustrated schematically in the diagram in FIG. 10.

A low-cost insulating material is cut into strips. This dielectric 60can consist of PET (polyethylene terephthalate), PEN (polyethylenenerephthalate), paper, ABS (acrylonitrile-butadiene-styrene), PVC(polyvinyl chloride) or any other known low-cost insulating material.

The dielectric strip 60 can advantageously have a non-conductiveadhesive face able to receive the gluing of the chip 10.

When the dielectric 60 is cut out in a strip, reference holes to thepitch of the pattern (for example 9.5 mm) are produced in ordersubsequently to serve for the gluing of the chip 10 with precision.

According to the variant embodiments, the reference holes can bereplaced by targets previously printed on the dielectric 60.

The chip 10 is then glued to the dielectric 60 with precision to thepitch of the chosen pattern.

According to variants, the adhesive of the dielectric strip 60 isthermoactivated for gluing of the chip 10 hot, or is composed of a“tack”, which designates an adhesive at room temperature for gluing thechip 10 cold.

It is also possible to effect a deposition of glue on the dielectric 60and to stick the chip 10 on this deposit of glue.

The precision of the gluing will be ensured by the referencing of theholes and/or targets previously produced on the dielectric strip 60.

In parallel, a metallic grid 18 is produced based on a copper alloy forexample, and covered with an electrolytic deposition adapted to the typeof connection which it is wished to produce, for example gold or nickel.

According to one particularity of the invention, this grid 18 is archedonce or twice according to conventional arching methods, by a punch forexample.

In the variant embodiment illustrated in FIG. 5, the grid is archedtwice.

A first arch 80 is intended to encase the height of the chip 10 and itsprotrusions 12 in order to place the connection areas 19 b on the grid11 and the protrusions 12 opposite each other.

A second arch 81 is intended to encase the step on the dielectric strip60 so as to obtain a micromodule 100 which is perfectly flat on thecontact 19 a side. Thus the dielectric 60 is flush with the contactareas 19 a on the grid 18 whilst leaving them free so as to providecommunication from the circuit towards the outside.

The variant embodiment illustrated in FIG. 6 has only the first arch 80.

The grid 18 and the dielectric 60 are then laminated.

The second arch 81 facilitates the lamination of the dielectric 60 onthe grid 18 whilst forming a guide for the dielectric strip 60.

The lamination, carried out by means of the references on the dielectricstrip 60 and/or by means of the second arch 81, put the connecting areasat 19 b on the grid 18 opposite the contact pads 11 possibly providedwith protrusions 12 on the chip 10.

It should be noted that, the chip 10 being connected below the grid 18,the contact areas 19 a on the grid 18 will be directly incorrespondence, via the connection areas 19 b, with the pads 11 on thechip 10. Consequently the problem of having to produce an adapted andcomplex pattern, as is the case in the connections according to the“flip chip” methods described above, will not be posed.

It is then necessary to effect the connections of the pads 11 on thechip 10 to the connection areas 19 b on the grid 18.

To this end, different known methods can be used, such as for examplelaser welding methods, or deposition of an anisotropic adhesive or athermocompression method, or by activation of the conductive polymerprotrusions previously deposited on the contact pads 11 on the chip 10.

It is advantageous, as already disclosed with reference to the priorart, to laminate an adhesive 25 which can be reactivated by heat orpressure over the entire useful surface of the grid 18.

Advantageously, the adhesive 25 has insulating properties in order toconstitute additional protection for the chip 10. This is because theadhesive 25 is not perforated as was routinely the case in the priorart.

Depositing a protective resin on the chip 10 can therefore be completelyexcluded in this manufacturing method.

The micromodule 100 is then cut out by means of a punch or a laser beam,and then fitted in the cavity of a card body by reactivating theadhesive 25 or depositing a drop of glue of the cyanoacrylate type, forexample, in the cavity.

FIG. 7 illustrates the step of insetting the micromodule 100 in thecavity 120 of the card body 100, by the technique of hot pressing inorder to reactivate the adhesive 25.

This figure shows clearly that hot pressing is not applied to thedielectric 60, but solely to the metallic grid 18, the punch 24 having arecess corresponding to the dielectric 60.

Likewise, if a technique of attachment with a glue of the cyanoacrylatetype had been chosen, the glue would have been applied between thecavity 120 of the card body 100 and the metallic grid 18 covered or notwith the adhesive 25, and not on the dielectric 60.

FIGS. 8 and 9 illustrate respectively schematic views from below andabove of the micromodule obtained by the method according to theinvention applied to contact cards.

FIGS. 5 and 6 are sections A—A of FIG. 8.

FIG. 8 shows clearly the arches 80 and 81 on the metallic grid 18, thefirst delimiting the contact areas 19 a and the connection areas 19 b,and the second possibly delimiting the zone of the dielectric strip 60.

FIG. 9 shows the external side of the micromodule, on the ISO contactsside.

According to one of the variants, disclosed previously, the dielectricstrip 60 is flush with the contact areas 19 a on the metallic grid 18.The outside of the smart card thus obtained is therefore perfectly flat.

In the other variant, the dielectric strip 60 will form a small step onthe top of the contact areas 19 a.

In addition, the connection terminal block 18 on the chip card obtainedhas a middle zone corresponding to the dielectric strip 60 on which alogo or drawing can be printed (preferentially directly at the time ofcutting out of the insulating material in strip form). This face of thedielectric strip 60 can possibly be in different colours and/or carrythe serial number of the card.

FIGS. 11 and 12 illustrate a third embodiment of a micromodule accordingto the invention which applies to contactless cards or electroniclabels.

FIGS. 11 and 12 illustrate respectively a plan view and a view intransverse section of the manufacturing method according to this thirdembodiment of the invention.

The method described previously for contact cards is repeated, theoperation of laminating the arched grille 18 on the dielectric 60 beingall the easier since the number of contact pads 18 on the chip 10, withor without protrusion 12, to be connected to the connection areas 19 b,is only two.

Moreover, protection of the chip 10 is obtained by laminating a solidfilm 26 over the entire surface of the micromodule 100. All the problemsof the prior art related to the deposition of a drop of resin forprotection by encapsulation or overmoulding are therefore avoided.

In addition, as illustrated in FIG. 11, it is possible, in the contextof this application, to laminate as many dielectric strips 60 aspossible in order to optimise the number of micromodules on a grid 18.

FIG. 12 illustrates the connection of the micromodule 100 with anantenna 50, carried out according to standard techniques.

Advantageously, the dielectric 60 can serve to isolate the contacts 55from the other turns on the antenna 50, in the case of a screen-printedantenna. This makes it possible to avoid the screen printing of aninsulant on the central turns.

What is claimed is:
 1. A method for manufacturing a portableintegrated-circuit electronic device having a module comprising anintegrated-circuit chip attached to a dielectric support and connectedto a metallic grid having contact areas and connection areas, comprisingthe steps of producing a housing for a chip on a metallic grid byarching the grid, said housing being dimensioned to receive thethickness of the chip and its contact pads, and laminating said grid onthe dielectric support to place each contact pad on the chip oppositeand in connection with a corresponding connection area on the grid.
 2. Amanufacturing method according to claim 1, wherein the dielectricsupport comprises a band leaving the contact areas on the metallic gridfree.
 3. A manufacturing method according to claim 2, wherein themetallic grid also has a second arch to encase the thickness of thedielectric strip so as to place the dielectric strip flush with thecontact areas on the metallic grid.
 4. A manufacturing method accordingto claim 1 wherein the dielectric strip comprises a polyethyleneterephthalate (PET).
 5. A manufacturing method according to claim 1wherein the dielectric strip comprises anacrylonitrile-butadiene-styrene (ABS).
 6. A manufacturing methodaccording to claim 1 wherein the dielectric strip comprises paper.
 7. Amanufacturing method according to claim 1 wherein the dielectric stripcomprises a polyvinyl chloride (PVC).
 8. A manufacturing methodaccording to claim 1 wherein the dielectric strip has an adhesivesurface for gluing the chip on said strip.
 9. A manufacturing methodaccording to claim 1 further including the step of producing referenceand/or target holes on the dielectric strip to effect a precise gluingof the chip on said strip.
 10. A manufacturing method according to claim1 wherein the connection of the contact pads on the chip to theconnection areas on the grid is effected by laser welding.
 11. Amanufacturing method according to claim 1 further including the steps ofdepositing protrusions made of conductive polymer material on thecontact pads on the chip, and connecting the contact pads on the chip tothe connection areas on the grid by hot lamination.
 12. A manufacturingmethod according to claim 1 further including a step of attaching themodule in the cavity of a card body.
 13. A manufacturing methodaccording to claim 12, wherein the attachment of the module is effectedby activation of an adhesive film previously laminated over the entiresurface of the metallic grid.
 14. A manufacturing method according toclaim 13, wherein the adhesive film also constitutes an insulantproviding protection of the chip.
 15. A manufacturing method accordingto claim 1 further including a step of connecting the module to anantenna.
 16. A manufacturing method according to claim 15, wherein thechip is protected by lamination of an insulating film over the entiresurface of the metallic grid.
 17. A manufacturing method according toclaim 15, further including the step of insulating central turns of theantenna with the dielectric strip.
 18. An integrated-circuit electronicmodule comprising an integrated-circuit chip attached to a dielectricsupport and connected to a communication interface having contact areasand connection areas, wherein the communication interface includes anarched metallic grid, the arch defining a housing for a chip and beingdimensioned to receive the thickness of the chip and its contact pads,and wherein the connection areas on the grid are situated respectivelyopposite and in connection with the contact pads on the chip.
 19. Anelectronic module according to claim 18, wherein the dielectric supportcomprises a strip leaving the contact areas free.
 20. An electronicmodule according to claim 19, wherein the metallic grid has two distinctarches, a first arch encasing the thickness of the chip and its contactpads, and a second arch encasing the thickness of the dielectric strip.21. An electronic module according to claim 18 further including aprotective film disposed over the entire surface of the metallic grid.22. A portable integrated-circuit device such as a smart card or anelectronic label, containing an electronic module comprising anintegrated-circuit chip attached to a dielectric support and connectedto a communication interface having contact areas and connection areas,wherein the communication interface includes arched metallic grid, thearch defining a housing for a chip and being dimensioned to receive thethickness of the chip and its contact pads, and wherein the connectionareas on the grid are situated respectively opposite and in connectionwith the contact pads on the chip.